Attrition rates and time to completion of PhD candidates has internationally become a concern of governments, universities and the candidates themselves. Suggestions that attrition is too high and, for those candidates who do complete, enrolment times are too long were investigated. Two separate datasets were used, one based initially on all 1195 PhD enrolments between 1988 and 1999 recorded at one Australian university, the other based on 601 candidates submitting PhD theses during 2001-2003 at six Australian universities. Two measures of enrolment time were used; total elapsed time from first enrolment, and candidacy time in equivalent full-time semesters. It was found that 51% of 698 candidates who had the opportunity to be enrolled for at least four years successfully completed a PhD and that, after six years, 70% had successfully completed. For the one university included in both datasets, average candidacy time increased from 7.4 semesters for the first dataset to 7.9 semesters for the second, with marked differences between Broad Fields of Study. The median elapsed time was 4.4 years. A range of candidate, candidature, discipline and institution variables in multiple regression analyses including the six universities explained 39% of variation in elapsed time and 22% in candidacy time.